Ratchet spanner



oct. 13, 1970 GUNJI .MAEDA A335533,315

RATCHE'I SPANNER Filed sept.A 23, 1968 y VVE/:frog BY GUNJI MABDA United States Patent O 3,533,315 RATCHET SPANNER Gunji Maeda, Aslya, Hyogo, Japan, assgnor to Maeda Metal Industries, Ltd., Higashinariku, Osaka, Japan Filed Sept. 23, 1968, Ser. No. 761,459 Int. Cl. Bb 13/46 U.S. Cl. 81-60 2 Claims ABSTRACT oF THE DISCLOSURE This invention relates to a ratchet Spanner wrench having an annular ring member on the end of an elongated handle, with a plurality of uniform, symmetrically angled ratchet teeth engraved on the inner periphery of the ring member. A driving member having a central cylindrical hub or radially extended ange is rotatably disposed within the confines of the toothed portion of the ring, and stub drive shafts project from each side of the hub, the shafts being adapted to coact with a tool or fastener socket. A pair of resiliently biased detents are slidably recessed in opposite sides of the hub in a chordal manner relative thereto and are normally biased outwardly in opposite facing directions to engage the ratchet teeth at substantially right angles, said detents are operably engaged by said teeth to effect rotation of the driving member, responsive to driving rotation of the handle operated ring member, whereas the ratchet teeth are adapted to slide past the detent means with no relative movement of the driving member when the ring is rotated in the reverse direction. By using two oppositely disposed detents, the torque driving load is imposed equally thereon, resulting in considerably reduced wear load on each detent and the ratchet teeth.

This invention relates to a ratchet Spanner wrench, in the mechanism of which the driving member is turnably inserted in the outside ring of its head part with its ratchet teeth engraved on the inner surface thereof, and two small spring-biased detents are provided for complemental engagement with ratchet teeth in reverse, symmetrically opposed positions on the circumference of the said driving member, so that when the outside ring is turned integrally with the driving member, the torque may act as a couple on the driving member through the two detents mentioned above.

In known conventional ratchet spanners, a detent is provided engagingly between the outside ring attached to the handle and the driving member inserted in a socket therein to drive them, and the torque applied by the handle is transmitted to the driving member through this detent. In this respect, a locally concentrated pressing force corresponding to the torque transmitted is applied on the ratchet teeth engraved on the inner circumference of the outside ring or on the outer circumference of the driving member, thereby causing relatively rapid wear of the detent or the ratchet teeth caused by the resultant excessive stresses. Further, a pressing force which during assembly pushes the driving member to the inner surface of the outside ring may be applied on the driving member causing disguring teeth marks to be applied on the circumference of the driving member or the outside ring in the axially symmetrical position to the detent.

The objects of this invention are to provide improved ratchet type wrenches in which the torque transmitted through the spaced detents acts upon the driving member as a divided couple,.whereby the loads imposed on the detents and the ratchet teeth are reduced, and at the same time, the force pushing the driving member onto the ratchet teeth counteract each other, thereby precluding undesirable defacing by the imparting of teeth marks on the surface of the driving member.

These and other objects and advantages of the present invention will become apparent from a reading of the following detailed specification and the appended claims together with the illustrative drawings, in which:

FIG. 1 shows a perspective View of the improved Spanner of this invention;

FIG. 2 is a fragmentary horizontal cross-sectional detail view as taken on the line 2 2 in FIG. l; and

FIG. 3 is a fragmentary transverse cross-section view as taken on the line 3-3 in FIG. 2.

Referring to the drawings, the ratchet head portion of the wrench is generally denoted 1, having an integrally or unitarily attached handle 2, and shown in association with a driving member 3 and socket iitting 4. The head portion includes an outside ring 12 having the ratchet teeth 11 suitably formed on the inner peripheral surface thereof, and part of the outer circumference of the outside ring 12 is projected outwardly to be fused or otherwise unitarily rigidly joined to the handle 2.

The driving member 3, shown inserted into the outside ring 12, comprises a middle circumferential, radially extended ange or hub 31 having an outside diameter nearly equal to the inner circumference of the outside ring 12, and further includes the multisided, wrenchsocket inserting stub shafts 32, 32 axially projecting from the opposite central surfaces of the flange 31. It is apparent that stubs 32 coact in a conventional manner with and to a hold socket `4 and/ or a bolt head, or the like, inserted thereon. In symmetrically opposite positions on the circular circumference of said flange part 31, a pair of oblong holes 33, 33 of a specified size and depth are bored and otherwise suitably formed to constitute detent slideways in a nonradial direction of the flange and approximately at a right angle to the inclined surfaces of the ratchet teeth 11. In each oblong hole 33 there is yieldably disposed a detent 34 having its tip inclined to complementally match the shape of the ratchet teeth 11, said detent being biased normally outwardly by a spring 35 seated therebeneath in said hole 33, to effect engagement with the associated ratchet teeth 11.

The driving member 3 is retained centrally within ring 12 between annular washers 5, 5 held in place by expansion retaining rings 6, 6 which snap into complementally formed grooves 6a, 6a respectively disposed inwardly adjacent the opposite faces of the ring 12.

The outer opposite stub shafts 32, 32 are provided in one of their sides with the conventional spring biased ball detent 7, for complemental coaction with the various wrench sockets 4 or the like as used therewith.

In operating the improved wrench, when the handle 2 is turned in the direction to rotate the head as indicated by the arrow a, adjacent concave disposed faces 15 and 16 of the ratchet teeth exert component reacting forces against the detent 34 forcing it frictionally against inner face 17 of the detent recess slideway, responsive to the detent 34 exerting initial direct component forces against said faces 15 and 16, thereby turning the driving member 3 integrally with the head portion 1, and in turn, driving the socket and the like inserted on the axial stub shaft 32. On the other hand, when the handle 2 is reversely turned in the direction of arrow b, there is no such binding force exerted by tooth face 15, and the nearly direct force applied by tooth face 16 to the end of detent 34 causes it to be pushed in, wherein the detent 34 is retractively forced into the slideway portion of the oblong hole 33, thereby allowing the ratchet teeth 11 to ride freely over the detent 34.

As the outside ring 12, and the driving member 3 rotate together in the drive direction, the ratchet teeth 11 are simultaneously drivingly engaged by the two detents 34, 34. As a result, the torque to the driving member 3,

which corresponds to the transmitting torque, is imposed equally on each detent, and consequently, the loads imposed via the detents 34 upon the ratchet teeth 11 meshed therewith are also reduced in half. Moreover, because the pressing forces applied as mentioned above are of the same directional forces opposing one to the other, these forces exactly counteract each other and work as a couple. For this reason, the outside ring 12 and the driving member 3 are held concentrically stable. With such a mechanism, the defacing disadvantages of causing teeth marks from the thrust of the ratchet teeth onto the surface of the driving shaft is precluded.

It is apparent from the foregoing that this invention halves the stress applied to the ratchet teeth 11 and the detents 34, as compared to that of the well known, prior art ratchet Spanner wrench. An added advantage of the present construction is that it can be used under greater loads. Further, it withstands its hard use without undue wear for a long time, the defacing of the circumference of the driving shaft by teeth marks resulting from the assembly thrust of the ratchet teeth is precluded, and continuously smooth operation with this Spanner is assured.

What is claimed is:

1. A ratchet Spanner wrench comprising in combination:

(a) an annular ring having a plurality of symmetrically obtusely angled ratchet teeth engraved on the innner peripheral surface thereof and handle means attachable on the outer peripheral surface;

(b) a driving member having a central hub portion rotatably disposable within said ring,

(c) stub drive shafts projecting from both sides of l said hub and adapted to coact with a tool or fastener socket; (d) a plurality of equilaterally disposed oblong holes or slideways formed in the outer peripheral hub portion and in dissimilar radial directions, non-axial of said stub shafts; said holes disposed in a chordal manner with respect to the outer periphery of the hub and substantially on the medial major plane of the hub portion, with each hole in a direction slightly oblique from a right angle to the opposite inclined surface of the coaligned ratchet teeth; and

(e) resiliently biased detent means including differently directed detents having complementally angled end faces for full mating engagement with said angled teeth, freely insertable and slideable within said oblong holes, said detent means and teeth equilaterally engaging to effect uniformly applied pressure rotation of the driving member responsive to driving rotation of the handle operated ring member.

2. A ratchet wrench as defined in claim 1 wherein the plural detents are housed in oppositely disposed, reversely facing slideways in said hub portion.

References Cited UNITED STATES PATENTS 1,578,065 3/1926 Bemus et al. 81-61 1,258,582 3/1918 McGuffey 81-61 1,644,079 10/1927 ONeill 81-59.1

FOREIGN PATENTS 1,218,907 12/1959 France.

970,73 1 9/1964 Great Britain.

JAMES L. I ONES, JR., Primary Examiner 

